The smile-filled photo shows Elton and Diana posing next to each other -- both in all black with intricate detailing, with Elton opting to add an ornate blue vest -- in front of a wood wall. The photo appears to have been taken sometime in the '90s, judging by their appearances.

"20 years ago today, the world lost an angel," he captioned the sweet photo. "#RIP"

Elton John's tribute is surely the first of many to come from Diana's famous friends.